Help: Possible Power Jack transformer

[christianrodher]

I bought the attached transformer on Ebay. It seems like a power jack transformer. Can this be use to split a 240v single phase AC output into 2 lines of 120v (split phase)? If so can anyone help me with the wiring diagram. If not what is the use of this transformer?

[Sid Genetry Solar]

25 minutes ago, christianrodher said:

It seems like a power jack transformer.

It is 😉

 

25 minutes ago, christianrodher said:

Can this be use to split a 240v single phase AC output into 2 lines of 120v (split phase)?

Yes, though it's only going to be good for 2-3kw max before it exceeds 80-90C.

 

25 minutes ago, christianrodher said:

If so can anyone help me with the wiring diagram.

Ignore the big red and black leads; that's the transformer "battery" side (intended for a 48vDC PJ inverter, judging by the label.) You'll probably want to put tape over them or something to prevent them from shorting out.

While I'm not 100% sure (PJ is very unpredictable!), the smaller leads on the other side of the transformer should be "L1 N L2", with the yellow lead being the Neutral line.  The small red/black wires here can go to 240vAC, and you'll have somewhere between 115-130vAC between red/yellow, and the same across yellow/black.

These transformers are notoriously imbalanced...so don't expect perfectly balanced phases.

 

49 minutes ago, christianrodher said:

If not what is the use of this transformer?

It's a transformer used in 48vDC "8kw" PJ (or "15kw" U-Power) inverters...which will only do 2-3kw before overheating.

[christianrodher]

Thanks for the fast reply!

11 minutes ago, Sid Genetry Solar said:

While I'm not 100% sure (PJ is very unpredictable!), the smaller leads on the other side of the transformer should be "L1 N L2", with the yellow lead being the Neutral line.  The small red/black wires here can go to 240vAC, and you'll have somewhere between 115-130vAC between red/yellow, and the same across yellow/black.

These transformers are notoriously imbalanced...so don't expect perfectly balanced phases.

So the black (L1 120v), Yellow (N) and the Red (L2 120v) are outputs. The big ones are 48vDC. So where do I input the L1 240v and N ?

[Sid Genetry Solar]

1 hour ago, christianrodher said:

Thanks for the fast reply!

So the black (L1 120v), Yellow (N) and the Red (L2 120v) are outputs. The big ones are 48vDC. So where do I input the L1 240v and N ?

If used for an inverter, yes, that is the hookup.

 

But if you're using it as an autoformer, then wire it up as I described above:

1 hour ago, Sid Genetry Solar said:

Ignore the big red and black leads; that's the transformer "battery" side (intended for a 48vDC PJ inverter, judging by the label.) You'll probably want to put tape over them or something to prevent them from shorting out.

While I'm not 100% sure (PJ is very unpredictable!), the smaller leads on the other side of the transformer should be "L1 N L2", with the yellow lead being the Neutral line.  The small red/black wires here can go to 240vAC, and you'll have somewhere between 115-130vAC between red/yellow, and the same across yellow/black.

Small red/black wires go to "L1 / N 240v" (if you're using single-phase vernacular)...assuming that's how PJ wound this particular transformer.

It's rather important to keep your vernacular straight; a single-phase 240v system is the same as a 120v single-phase system: L and N.

However, those exact same "L / N" wires are "L1 / L2" if you are working with a split-phase 240v system.  Neutral becomes the middle wire generated by the transformer--though if you're planning on grounding anything here, use simple common electrical sense to avoid half the transformer out through grounding.

[christianrodher]

19 minutes ago, Sid Genetry Solar said:

But if you're using it as an autoformer, then wire it up as I described above:

Small red/black wires go to "L1 / N 240v" (if you're using single-phase vernacular)...assuming that's how PJ wound this particular transformer.

It's rather important to keep your vernacular straight; a single-phase 240v system is the same as a 120v single-phase system: L and N.

However, those exact same "L / N" wires are "L1 / L2" if you are working with a split-phase 240v system.  Neutral becomes the middle wire generated by the transformer--though if you're planning on grounding anything here, use simple common electrical sense to avoid half the transformer out through grounding.

I dont understand. I made a horrible diagram that shows what I want to acomplish. I dont know where to connect the "black" and "yellow" wires coming out of the inverter AC output to the transformer.

[InPhase]

To the small red and black wires of the transformer.

[dickson]

It's a transformer used in 48vDC "8kw" PJ (or "15kw" U-Power) inverters...which will only do 2-3kw before overheating.

To the small red and black wires of the transformer  AS3  

The load to the  small red and black wires  when use as an  autotransformer  must be less than 3000 watts or bad  thing will happen .  

[christianrodher]

5 hours ago, InPhase said:

To the small red and black wires of the transformer.

the 240 out of the inverter goes to the marked small red and black wires located in the black wire? 

 

[christianrodher]

5 hours ago, dickson said:

It's a transformer used in 48vDC "8kw" PJ (or "15kw" U-Power) inverters...which will only do 2-3kw before overheating.

To the small red and black wires of the transformer  AS3  

The load to the  small red and black wires  when use as an  autotransformer  must be less than 3000 watts or bad  thing will happen .  

This is my first time wiring a transformer. Im trying to understand the instructions. But if I use the small red and black wires to input the 240v single phase (L,N). How can those same wires be the output L1 and L2 of 120v and the Yellow be N.

[dickson]

This is my first time wiring a transformer. Im trying to understand the instructions. But if I use the small red and black wires to input the 240v single phase (L,N). How can those same wires be the output L1 and L2 of 120v and the Yellow be N.

Look at your diagram  and  the load connected  to the breaker box  red wire and  yellow N  will give 120 v  and a load connected to the black wire and the yellow N  will give 120v also  but if you connect the load to the red and black wire then  you have 240 v  like what is output of the solar inverter .    Should use a kill-a watt meter to make sure your load  is less than 3000  watt or doing this as an autotransformer is very dangerous .   

 

 

[dickson]

From your diagram  the yellow neutral  output wire  from the solar inverter  go to the  red wire of the breaker box  NOT the  yellow N  of the breaker box  and the  black wire output of the solar inverter go to the small black wire of the breaker box which is the same as the small black wire of the transformer .  The  2 large red and  black wire is taped up and not use and  NOT  connected . 

[dickson]

Your original diagram  .   The solar inverter yellow go to the red  small wire of the AS3 transformer .   The red wire of the breaker box and the yellow  N of the breaker box give 120v .     The  yellow wire of the solar inverter and the black wire of the solar inverter  give  240 vac .   

[Sid Genetry Solar]

3 hours ago, christianrodher said:

the 240 out of the inverter goes to the marked small red and black wires located in the black wire?

Ha, no.  That's a current sense device, you'll blow it up very quickly with 240v.

 

 

Try this:

 

Being a Chinese inverter, I doubt the ground point will have much to do with anything.  The serious issue comes in if it's tied/coupled to the inverter's "Neutral", which is being used as L2.  Shorting this L2 to the new Neutral generated by the transformer CAN cause serious issues, and it's best left unconnected IMO.

 

[TheButcher]

Whoops, I see this is a big transformer based inverter, not a HF inverter so the below doesn't apply.  That is all only for HF inverters, but it's still a good read so I'll leave it for posterity.

 

A low wattage 120 (or 240v, as appropriate) incandescent (the hot wire type) light bulb between the earth terminal and one of the AC output wires of the inverter is one way to test if it is safe to tie one of the AC output wires to earth and declare it neutral.  If the bulb lights even dimly, it is not safe to tie that AC output wire to earth.  With the bulb in place measure the AC voltage across the bulb.  It should be close to 0 volts.  If not, it is not safe to tie that AC output wire to earth.  Repeat the tests with the other AC output wire.  You can not measure the voltage without the bulb or a decent load in place as there definitely will be leakage voltage between the chassis earth and the AC output wires giving an approx 1/2 AC voltage reading.

Be especially wary of 120VAC single phase inverters that have a terminal strip and have 4 terminals.  They are almost certainly 120/240 split designs that are simply being run at low output voltage.  What you have on the terminal block is chassis earth, L1, 'neutral', L2.  The neutral terminal is at half line voltage (60VAC) with respect to the chassis earth terminal.  'Reliable Electric' had a few models like that.  Taking L1 or L2 to earth will blow transistors at power up of the inverter.  I have seen this style of inverter being sold as '240V' single phase into Europe / Australia / NZ etc, ie '240V' only countries.  The same caution applies there.  Connecting either of the AC output wires to earth to establish neutral = bang.

These particular designs aren't intrinsically unsafe.  A correctly installed RCD will still trip as current can flow from L1/L2 to the physical earth (ie a return path other than L1/L2) if you have tied the earth terminal to ... the earth.

Ultimately these things are not supposed to be wired up to premises wiring, even the ones that have terminal strips, but a technically competent person can ensure things are safe and don't go bang.

Edited November 25, 2021 by TheButcher

[christianrodher]

14 hours ago, Sid Genetry Solar said:

Ha, no.  That's a current sense device, you'll blow it up very quickly with 240v.

 

 

Try this:

 

Being a Chinese inverter, I doubt the ground point will have much to do with anything.  The serious issue comes in if it's tied/coupled to the inverter's "Neutral", which is being used as L2.  Shorting this L2 to the new Neutral generated by the transformer CAN cause serious issues, and it's best left unconnected IMO.

 

Thanks you very much, this forum is great!!! I will try this. Is the max safe watts of 2500-3000 is pre phase or total?

Edited November 26, 2021 by christianrodher

[dickson]

 Shorting this L2 to the new Neutral generated by the transformer CAN cause serious issues, and it's best left unconnected 

From this new  diagram  the red wire from the solar inverter  go to the red wire of breaker  box .   Do  NOT  connect the red wire of solar inverter to the  new Neutral  yellow wire generated  by the transformer AS3 .    

 the max safe watts of 2500-3000 is pre phase or total?   Use a kill-a-watt  meter to make sure the  total load is less than  3000  watts  and if it is a inductive  load  like a  microwave oven then  the  surge  must be less than  3000 watt .   One microwave  oven surge may be  5000 watt  but running  may be  2000 watt  and  bad thing may happen  because of the 5000 watt surge  that the AS3  can not handle .  

[christianrodher]

6 hours ago, dickson said:

 Shorting this L2 to the new Neutral generated by the transformer CAN cause serious issues, and it's best left unconnected 

From this new  diagram  the red wire from the solar inverter  go to the red wire of breaker  box .   Do  NOT  connect the red wire of solar inverter to the  new Neutral  yellow wire generated  by the transformer AS3 .    

 the max safe watts of 2500-3000 is pre phase or total?   Use a kill-a-watt  meter to make sure the  total load is less than  3000  watts  and if it is a inductive  load  like a  microwave oven then  the  surge  must be less than  3000 watt .   One microwave  oven surge may be  5000 watt  but running  may be  2000 watt  and  bad thing may happen  because of the 5000 watt surge  that the AS3  can not handle .  

I there any website to buy one that supports 5000watts? I saw in Genetry solar youtube video that he had some for selling, but cant find them in the store.

[Sid Genetry Solar]

1 hour ago, christianrodher said:

I there any website to buy one that supports 5000watts? I saw in Genetry solar youtube video that he had some for selling, but cant find them in the store.

If you just want a split-phase output from a Chinese HF inverter, then what you are looking for would be called an "autotransformer".  I wouldn't count on a PJ transformer to do this very well; they are terribly imbalanced (in both winding specification and wire size).

You can try the one you have...worst case, it'll overheat (you would be advised to keep a close watch on it, as without thermal protection, an overheated transformer can easily start a fire.)

 

8 hours ago, dickson said:

Use a kill-a-watt  meter to make sure the  total load is less than  3000  watts  and if it is a inductive  load  like a  microwave oven then  the  surge  must be less than  3000 watt .   One microwave  oven surge may be  5000 watt  but running  may be  2000 watt  and  bad thing may happen  because of the 5000 watt surge  that the AS3  can not handle .  

Ah now...the transformer will handle surges well past 6kw, just not for very long.  Don't think that's to the fusing point of the winding yet 😉.

 

9 hours ago, christianrodher said:

Is the max safe watts of 2500-3000 is pre phase or total?

Total load.

[dickson]

I there any website to buy one that supports 5000watts? I saw in Genetry solar youtube video that he had some for selling, but cant find them in the store

I  use the 352 dollar  autotransformer  for microwave oven  but  bad thing happen  when use with heat pump .

[dickson]

Comment about  autotransformer  on youtube .

[christianrodher]

I was looking at the Gentry Solar inverter also. But I don't know how to add the futures of the Chinese hybrid inverters to it.

For example:

1)it charge the battery from Solar and Grid/Gen

2)If battery goes very low it transfers the load to grid while it charges the battery to certain voltage.

Is there any guide to add all the hybrid futures to Gentry Solar standalone inverter?

[TheButcher]

I'll let you in on a secret, well not really a secret.  The Chinese 'hybrid' probably just has a standalone bare solar charger in box.  If you want an example you can find 'unboxing' videos on youtube where people unpack and take the lid off Chinese LF hybrid inverters.  Pay attention and you might just see a separate solar charger in there.

So the answer to how do you add a solar charger to the GS inverter?  Buy any solar charger you like and wire it to your battery bank as you normally would (ie, follow the instructions).

[christianrodher]

2 minutes ago, TheButcher said:

I'll let you in on a secret, well not really a secret.  The Chinese 'hybrid' probably just has a standalone bare solar charger in box.  If you want an example you can find 'unboxing' videos on youtube where people unpack and take the lid off Chinese LF hybrid inverters.  Pay attention and you might just see a separate solar charger in there.

So the answer to how do you add a solar charger to the GS inverter?  Buy any solar charger you like and wire it to your battery bank as you normally would (ie, follow the instructions).

but the grind charging and 10ms auto-transfer to grid on low battery voltage part? that is in the charger setup also?

[Sid Genetry Solar]

27 minutes ago, christianrodher said:

1)it charge the battery from Solar and Grid/Gen

Genetry Solar inverters can charge the battery from AC input (Grid/Gen)

 

27 minutes ago, christianrodher said:

2)If battery goes very low it transfers the load to grid while it charges the battery to certain voltage.

Already implemented.  All settings are fully adjustable (within reasonable ranges), so you can specify exactly at what voltage you want the transfer (TO and FROM grid) to occur.  Transition from battery to grid is currently seamless on Rev. C-based GS inverters (all current ones going out), while the return transition needs a tad of work 😉.  Safety is key, even if there's a bit of a glitch.

 

Like @TheButcher pointed out, yes, most "hybrid" inverters just throw a cheap, small MPPT into the box, and people think they got such a great deal.  I just saw a video about a SunGold Power 12kw inverter, and that thing has a laughable 145v max, 60A MPPT in it.  I mean, it will barely handle 3kw of solar...which means you will need external MPPT charge controllers--and then they're all different settings/mismatched, and it all goes down the tubes.  In a nutshell, that's why I currently do not plan to add an MPPT to GS inverters.

Also, said "hybrid" units more often than not give you either no settings...or at best, cursory settings.  GS inverters are FULLY customizable--and if you need something changed (within technically possible reason), it can be handled via firmware update.

[Sid Genetry Solar]

Sean demonstrated the current ATS functionality of the GS inverters in this video: